A Self-assembling Nanomaterial Reduces Acute Brain Injury and Enhances Functional Recovery in a Rat Model of Hypertensive Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) carries a high morbidity and mortality rate. High systolic blood pressure promotes hematoma growth. A self-assembling peptide (SAP) can achieve immediate hemostasis via formation of a SAP nanofiber scaffold (SAPNS). A minimally invasive aspiration of hematoma plus local delivery of SAPNS may lead to decompression of brain tissue and prevent hematoma growth. In a rat model of renovascular hypertension, experimental ICH was induced by a local injection of bacterial collagenase IV into the left basal ganglia. At 3.5 hours after induction of ICH, stereotactic clot aspiration or sham aspiration was performed manually. Following hematoma aspiration, an intrastriatal injection of 1% SAP, saline or sham injection was performed. Hematoma volume and brain swelling were quantified at 24 hours after ICH. Brain sections were immuno histochemically processed for myeloperoxidase and CD68 to detect the inflammatory infiltration in the perihematomal area. Perihematomal apoptotic cell death was determined using TUNEL staining. Functional recovery was assessed using neurological severity score and modified limb placement test at 1, 3, 7, 10 days after ICH. The combined treatment with hematoma removal and locally delivered SAPNS decreased hematoma volume, hematoma growth, brain edema, perihematomal inflammatory cell infiltration and apoptosis, as well as improved sensorimotor functional recovery. Locally delivered SAPNS after hematoma aspiration may prevent hematoma growth, facilitate the repair of ICHrelated brain injury and promote functional recovery. Such combined treatment may be effective in patients with hypertensive ICH. regular repeats of ionic hydrophilic and hydrophobic amino acids which are chemically synthesized and form extremely stable β-sheet structures in water. Thousands of peptides self-assemble to form a single nanofiber, and trillions of peptides or billions of nanofibers form the scaffold that contains ≈99.5% water and 0.5% peptide materials. The gelation process is charge dependent and accelerated either by changing to a neutral pH or by contacting physiological concentration of salt solutions. The scanning electron microscopy (SEM) image shows the scaffold after the assembly of all of the polypeptides (Figure 1). This peptide can form stable β-sheet structures and eventually turn into a hydrogel [8]. Previous studies in a hamster midbrain severed optical Citation: Sang LY, Liang YX, So KF, Leung GK, Ellis-Behnke RG, et al. (2014) A Self-assembling Nanomaterial Reduces Acute Brain Injury and Enhances Functional Recovery in a Rat Model of Hypertensive Intracerebral Hemorrhage. J Nanomed Nanotechnol 5: 224. doi: 10.4172/2157-7439.1000224